power: supply: smb1355: Add support to make SMB1355 driver GKI compliant

Add support for "parallel" power supply which is not present in 5.4
kernel through IIO device and properties under it through IIO channels
under the IIO device.

Change-Id: I2f7fe8d96080ea927f1349a6742cd4e0a6ffc290
Signed-off-by: Shyam Kumar Thella <sthella@codeaurora.org>
Signed-off-by: Ashish Chavan <ashichav@codeaurora.org>